Art of making one-piece window envelopes



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w. E. swam- ART OF MAKING ONE-PIECE WINDOW ENVELOPES' June 2, 1

Filed July 1, 1921 Patented June 2, 1925.

UNITED STATES I 1,540,395 PATENT OFFICE.

WILLARD E. SWIFT, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO UNITED STATESENVELOPE COMPANY, OF SPRINGFIELD, MASSACHUSETTS, A CORPORATION 0]? MAINE.

ART OF MAKING ONE-PIECE WINDOW ENVELOPES.

Application filed July 1,

To all whom it may concern:

Be it known that I, WILLARD E. Swim, a citizen of the United States,reslding at Worcester, in the county of Worcester and Commonwealth ofMassachusetts, have invented a new and useful Improvement in the Art ofMaking One-Piece Window Envelopes, of which the following, together withthe accompanying drawings, is a specification.

The present invention relates to the manufacture of window envelopes ofthe one piece type, viz, those in which an integral portion of the faceof the envelope is rendered transparent or semi-transparent, for thedisclosure through same of the address on the enclosure. Such windowenvelopes are to be distinguished from the two piece type, wherein aseparate transparent patch 1s secured, b adhesive or the like, over anopening cut 1n the face of the envelope.

The process of making a one piece window envelope involves, among otherthings, the treatment of a portion of the envelope blank with a suitablepenetrating varnish which has the faculty of so reacting on the fibersof the paper as to partially destroy the opaque character of the same.Such varnish is applied, preferably, to the inside surface of the flator extended envelope blank, so that when said blank is folded, the outersurface of the envelope is devoid of the stickiness that the use of sucha varnish inevitably entails. Heretofore in the manufacture of one piecewindow envelopes, the application of the varnish, for the purpose ofproducing a transparent or a semi-transparent window in the unfoldedblank has been carried out as a separate, detached, and independent stepin the manufacture of such envelo es; after receiving their imprints ofvarnis 1, the blanks have to be removed separately from the imprintingmechanism and placed in trays, in such manner as to revent theirsticking together or smearlng. The trays are then placed in an oven andafter the varnish has penetrated and has sufliciently dried the traysare removed and the blanks are assembled, by hand, into stacks, inreadiness for the subsequent folding operation. The manufacture of oneiece window envelopes by the process above described is wasteful oftime, space and 1921, Serial 1W0. 4a1,s5a.

material; moreover, it requires a large amount of special equipment, inthe form' their stacking, preparatory to folding, be-.

ing accomplished automatically, by a series of related steps. Themode ormanner in which such continuous manufacture is obtained, will be fullyset forth in the following description, reference being had to theaccompanying drawings, wherein Figure 1 is a sectional representation ofthe connected 'instrumentalities for successively conveying, imprinting,drying and stacking the blanks, in accordance with the invention.

Figure 2 is a perspective diagrammatic showing of the successive stepsin the treatment of the blanks.

Like reference characters refer to like parts in the different figures.

As indicated at the left hand side of Fig. 1, a suitable stack ofuntreated blanks, represented by the numeral 1, is disposed in operativerelation to a, suction of other pickup mechanism 2, the blanks beinguniformly arranged in the stack 1 with their inside surfaces uppermost,The pick-u mechanism 2 may be of any type, well known in the art, andadapted to seize successive topmost blanks of the stack 1, and presentthem, flatwise, to a suitable feeding mechanism 3, here shown asconsisting of horizontal sets of endless belts or bands 4, 4, which runon suitable rollers 5, 5. Each blank as conveyed flatwise on the feedingmechanism 3, is adapted, before its delivery from said feeding mechanismto be definitely centered and squared; any suitable means may beemployed for this purpose, as for instance a set of gaging stops 6 whichare moved by a cam 6' intermittently, into and out of the path of thesuccessively fed blanks.

Disposed in relation to receive the inditutes a bed plate, beingsuitably covered for this purpose, and it is also provided with agripper 10, the latter operating 1n synchronlsm with the gripper 8 ofcylinder-,7, so that when said gripper 8 is opened to release the blank,the gripper 10 closes thereon and thus secures the transfer of the blankfrom the cylinder 7 to the cylinder 9, the latter rotating in acounterclockwise dlrection.

I It is to be noted that the blanks have their inside surfaces uppermoston the cylinder 7,.

but when transferred to the cylinder 9 their outside surfaces areuppermost. This affords opportunity for printing on the face of theenvelope a suitable margin to define the transparency, as indicated at11, Fig.

2. Such printing, while the blank is sup ported on the bed late affordedby cylinder 9, may be accomp ished by the cooperatio'n of a printing 0linder 12, the latter carrying a sultable ova or rectangular printingdie 13 which receives its supply ofink, at each revolution, fromsuitable transfer mechanism of well known form, here shown ascomposition rollers 14, 14, cooperating with a feed cylinder 15, thelatter being supplied by a vibrating roller 16 from an ink fountain 17.These printing instrumentalities, per se, form no part of the presentinvention, and hence need not be described in detail.

After each blank has received on its outer surface the printed margin,it is carried by the cylinder 9 and gripper '10 into tangenial relationto a third feed cylinder 18, the latter having a grip er 19 which closeson the forward edge of t 1e blank as the latter is released by thegripper 10. The cylinder 18 acts as a bed plate for a die 20 on a var-,nish imprinting cylinder 21, the die 20 being of the size and shapesuitable for imprinting an oval or rectangular window or transparency inthe blank, as shown at 22, Fig. 2. The operation of the several arts isso synchronized that the die 20 whic receives at each revolution asupply of var-* nish from transfer rolls 23, 23, is brought into contactwith the blank'on cylinder 18 just as the printed impression 11 becomestangent to the cylinder 21. The varnish penetrates the fibers of thepaper, being 'prevented from spreading bv the printed margin; thereaftersaid blank is transferred to a final gripper cylinder 24, whose gripper25 releases the blank as the latter approaches the plane of a horizontalconveying mechanism 26.

Said conveying mechanism 26 is shown here in the form of a pair ofendless chains 27 27 the latter providing suitable spaced pins orprojections 28, 28, which move the at blanks along suitable stationarybars or skids 29, 29. Chains 27, 27, pass over guide pulleys 30, 30, ateach end of the conveying mechanism. Intermediate said guide pulleys thechains pass through an elongated heating chamber or oven 31, the latterproviding any suitable heating means, such as steam, gas, orelectricity, for assisting the penetration and for evaporatin the excessmoisture in the varnish. The eating chamber 31 may be as long asrequired for this purpose, it being understood that the blanks aresuccessively conveyed therethrough in a continuous manner by theconveying mechanism, so as to emerge from the right hand end of saidheating chamber in a substantially dried condition. Chains 27,27,deliver the blanks one by one, to gripping devices 32, 32, here shownas'applied to an overhead band or belt 33,; the movement of the lattercauses the release of the gripper 32, by a cam 34, ust as the blank isregistered over a set of guide rods 35. Successive blanks pile up orcollect in this way by gravity on a p ate 36, in a uniform stack, andare thus in readiness, without any handling whatsoever for resentationto folding devices not shown, 0 any well known type.

I claim,

1. The improvement in the art of making one-piece envelopes whichconsists in printing window margins on the outer surface of successiveblanks, applying a liquid transparentizing material to the innersurfaces of said blanks, within the space defined by said printedmargins, moving said treated blanks successively, with their innersurfaces uppermost, through a heated chamber to dry the same, andprocuring their formation into a stack, by continuanceof said movementbeyond said chamber.

2. The combination with means for applying a liquid transparentizingsubstance to successively fed envelope blanks, of a travelling conveyoron which said treated blanks are successively deposited flatwise withtheir treated faces uppermost, a drying chamber through which saidtravelling conveyor passes, and means operable to remove successiveblanks from said conveyor, and by further movement thereof to assembletheminto a stack or pile.

3. The herein described method of making one-piece window envelopes in acontinuous manner, which consists in applying a liquid transparentizingsubstance to successively presented blanks, drying said blanks,successively, by movement of the lIU same, one by one, through a heatedchamber and rocurin the stackin of saidblanks, by gravity, bycontinuance of said movement.

4. The combination with means for applying a liquid transparentizingsubstance to successively fed envelope blanks, of a travelling conveyoron which said treated blanks are successively deposited, a dryingchamber through which said travelling conveyor passes, gripping means bywhich each blank is seized from above as it leaves said conveyor, andmeans for releasin said gripping means to permit the piling or stackingof said blanks by gravity.

Dated this 25th day of June, 1921.

WILLARD E. SWIFT,

